Blockable connector between sink drain and drainage stack.

ABSTRACT

Toward the enabling of cleaning schedules involving one or more chemical treatments for the disinfection of healthcare room sink drainsets to avoid nosocomial infections arising from the vectoring of drain pathogenic bacteria, a blockable novel connector is presented to connect a sink drainset to an existing wall stub leading to a drainage stack behind the wall. Multiple chemical soaks for the drainset can be enabled through elaboration of the blocking plug temporarily inserted into the adapter. Two configurations, sideways and upward, are possible to connect the wallbend straight to the connector, the upward allowing for orthogonal connection between the straight and the receiving hub of the connector whatever the angle an existing wall stub has to the wall upon which the sink is hung. Additional blocking plug technology can be enabled.

FIELD OF THE INVENTION

This Invention relates generally to sink drain systems with controlfeatures against colonization by pathogenic bacteria, and specifically,to the connection of sink drain systems to vertical drain stacks behindthe wall to which the sink is attached wherein the connection enableschemical scouring treatment as well as orthogonally aligned connections.

BACKGROUND OF THE INVENTION

The healthcare sink enables health care providers to practice handhygiene prior to, during, and after attending to their patient. Avariety of biological material gets washed down healthcare sink drains,leading to colonization of the drain by bacteria and othermicroorganisms. Drain microorganisms can originate not only from thesink side, but also from vertical drainage stacks or pipes connectingsink drains from floor to floor. For this reason once one sink becomescontaminated with pathogenic bacteria arising from patient material suchas blood or stool washed from the hands of a healthcare attendant,pathogens can travel by a plurality of means across, down, and even updrainage connections between sinks in neighboring rooms, to arrive at aneighboring patient room sink via the connection of the sink drain ofthat neighboring room to the vertical or horizontal drainage stackconnecting the original contaminated room sink with the neighboring roomsink.

When the drain of the newly colonized sink is colonized by pathogenicbacteria arising from a sick patient in a neighboring room, or frompathogenic bacteria from a previous patient of that room, bacteria havethe opportunity to travel by a plurality of means including but notlimited to aerosols, splash, and touch transmission. When sink drainbacteria travel to a patient in the newly colonized room, or from aprevious patient in that room, a patient can become infected with thistravelling pathogenic bacteria. This is called a nosocomial infection.Nosocomial infections can mean a patient can die from an infection thatthe patient did not have when entering the hospital. And a primary locusof nosocomial infection is the entire drainset of the sink from sink towall, where drainset refers to all the components including but notlimited to drain, tailpiece, trap, wallbend, and connector to thevertical drainage pipe. A sink drain, sometimes called a plug, is aflanged, externally threaded pipe suspended from the drainage hole inthe internal bottom of the sink bowl. A tailpiece is a tube runningvertically from the downstream outlet of a sink drain to the upstreamoutlet of a trap. A trap is a bent tube or cast or injected or forgedfitting in which drainage water collects in order to prevent sewer gasesrising up from the sewer in a vertical drainage stack from entering apatient room. To the downstream egress of the trap is attached awallbend, a bent pipe or tube leading to the vertical drainage stackcomprised of one or more pieces. The wallbend is connected to the stackby a connector, the focus of this Application.

An overlay on simple nosocomial infection is the ready sharing of mobileresistance genes between bacteria meeting somewhere in the drainset of ahealthcare sink. As bacteria move along a connection offered by adrainage stack and drainsets, bacteria evolve and accumulate antibioticresistance through the sharing of genetic information. Thistransformation of a hospital drainage system into a bioreactor for theevolution of pathogens with multiple resistances for a range ofantibiotics was not intended, and needs to be managed to heightenpatient safety. A plurality of tools to control drainset bacterialcolonization include but are not limited to sink design, drain design,tailpiece length, trap technologies, and chemical disinfectionprocedures.

One tool would be to remove sinks entirely from healthcare rooms. Thisis inconvenient for healthcare attendants for a plurality of reasons.Another sink option is to improve sink design to minimize effects thatlead to bacterial vectoring that include but are not limited to splash,poor housekeeping owing to the provision of flat surfaces on the sinkinviting temporary placement of objects moved elsewhere later, andaerosolization arising from direct impact of a supply faucet waterstream on a drain grid. Whether these changes have real impact onpathogen control is rarely tested in gold standard, double blindunbiased experimentation, but does encourage replacement of old sinkswith new sinks of different geometries, including but not limited tooffset sinks, where the drain in the sink bowl is located off center ofa central drain spout, avoiding direct contact of a supply water streamwith the drain. Usually there is limited wall width for a sinkinstallation, meaning that the line up or orientation of the drainoutlet of a new offset sink does not match the orientation of apre-existing drainage connection at the wall. This situation can preventan orthogonal connection, as defined below.

The term orthogonal in connecting plumbing tubes and hubs describes ajoining of a tube to a hub where the centerlines of both hub and tubeare coincident. Without orthogonality a wallbend tube might be crookedlyinserted and fixed into a hub, but with strain captured by theconnection in the form of stress in the wallbend, the connector, or thesoldering or solvent cementing of the connection itself. While adifference in height of the connection relative to the bottom of thedrain tailpiece can be matched by cutting down a long tailpiece, andwhile a difference in the length of separation between the centerline ofthe drain and the centerline of the vertical drainage stack behind thewall can also be adjusted by cutting down a long wallbend; in contrast,often the angle of an existing wallbend at the connector cannot beorthogonally matched to the angle of the wallbend connector port of aconnector relative to the wall, leading to a plurality of quick fixsolutions, including but not limited to flexible rubber connectors andapplication of torque to a wallbend to make it fit, with predictableimpacts on drainage seal, provision of foci for bacterial growth, andthe integrity of the drain system, as will be discussed below as asecondary design focus in this Application.

To continue with the drainset, drain design and tailpiece length areother potential tools to limit pathogen spread. Again, experimentalevidence must be collected from designed experiments. The challenge isthe same as with investigating the performance of changed sinkgeometries: the statistical sample size necessary to generate resultswith a high degree of confidence can run to many years of testing overhundreds if not thousands of sinks in busy ICU rooms. Furthermore, thisalso requires access to patient swab data, a legal barrier. Such studiesare expensive and rare, and even if successful, may not apply to apathogen newly emerging after the study.

Similarly, drain trap technologies can be used as tools to controlbacterial colonization of traps with pathogenic microorganisms. The trapof a drain is a U-shaped bend of pipe or cast or injected or forgedmaterial through which drain water passes on its way to the verticaldrainage stack. Technologies that can be added to the trap include butare not limited to heat, electrical potential difference, antimicrobialcoatings, ultraviolet light, and removable traps for sterilization. Allof these technologies introduce great capital and maintenance expense towhat is otherwise a very inexpensive part.

Downstream to the trap of the sink drain system is the wallbend, a bentpiece of tube (external diameter controlled) or pipe (internal diametercontrolled) emanating vertically from the downstream end of the trap,bending ninety degrees to form a horizontal tube or pipe, finallyconnecting to the horizontal connection on the vertical, or at timeshorizontal, drainage stack. Wallbend infection management tools includebut are not limited to antimicrobial materials and slippery internalcoatings.

In hospitals around the world at the time of writing of thisapplication, certain pathogenic bacterial species with multipleantibiotic resistance genes, called superbugs, colonize sink drainsystems and cannot be eradicated by sink geometry, drain design,tailpiece length, trap technology, wall bend technology, or anycombination of these tools. Standard disinfection regimes used interminal cleaning of rooms, that is, the thorough cleaning of ahealthcare room after a patient leaves it permanently, are also noteffective against colonization by superbugs. Colonization of connectingdrainage vertical stacks worsens this situation—cleaning one drainsystem leaves it open to re-infection by pathogenic bacteria lurking inthe drainage stack.

Herein lies the primary focus of this Application. Even if a series ofchemicals poured down the drain could effect albeit temporary kill ofpersistent bacterial colonization, the effect is limited as there is nosignificant residence time in the drainset. The chemicals merely flowthrough the drainset. A tool to increase residence time of chemicalswithin a drain system could include a drainage stop at the drainageconnection between wallbend and the vertical drainage stack. This is aprimary design focus of this Application.

SUMMARY OF THE INVENTION

Accordingly, it is an object of this invention to at least partiallyovercome some of the disadvantages of the prior art.

The key to sterilization of sink drainsets by chemicals is to addblockable functionality to the most downstream part of the sinkdrainset, in order that chemicals may be held long enough for them tokill bacteria lining the drain system between the sink and the wall.This can be accomplished using the connector Invention described in thisApplication. A secondary benefit of this connector is that it allows fororthogonal connection of the drainset wallbend to the connectionattached to the downstream drainage stack, usually vertical. Keyfeatures of said connector are that it may be installed in an upward orsideways connection style depending on whether the wallbend has two orone ninety degree bends respectively, that the connector has a sealingcleanout port allowing for access for unblocking and optionally othertechnologies, and that the connector has a blocker that fits sealinglyto the connector to block drainage of the sink drain system to enableextended chemical treatment.

A review of connection terminology is in order. A pipe is an outerdiameter controlled hollow cylinder; a tube is an internal diametercontrolled hollow cylinder; a hub or expansion is an expanded diameterterminus to a tube or pipe that allows for slidingly sealed insertion ofa tube or pipe end; a thread ring is an external thread feature on theend of a hub; a basket nut is a compression nut adorned with a flatannular feature perpendicular to the centerline of a hub that encirclesa piece of tube inserted into a connection hub and presses down onto theflange of an annular flanged seal provided in the internal diameter ofthe proximal hub end of an expansion hub during the process of threadingsaid basket nut onto a thread ring provided around the proximalexpansion terminus of the connector hub wherein the annular seal isplaced; a solder joint being a heated metal seal between a tube and ahub, a solvent seal is a chemical bonding treatment between a plasticpipe and hub. More recently, an annular metal grip with seal has beenadded to connection technology used in plumbing.

BRIEF DESCRIPTION OF THE DRAWINGS

In the drawings, which illustrate embodiments of the invention:

FIG. 1 shows a front view of a sink and trap in a side connectionconfiguration;

FIG. 2 shows an isometric view of sink and trap in a side connectionconfiguration with a cleanout cap on;

FIG. 3 shows an isometric view of sink and trap in a side connectionconfiguration with cleanout cap off;

FIG. 4 shows an isometric view sink in trap in side connectionconfiguration with a blocker out;

FIG. 5 shows an isometric view sink in trap in side connectionconfiguration with a blocker inserted;

FIG. 6 shows a front view of sink and trap in an upward connectionconfiguration;

FIG. 7 shows a side view of sink and trap in an upward connectionconfiguration;

FIG. 8 shows a lateral cutaway of side detail of closeable connectionshowing blocked egress of upstream drain;

FIG. 9 shows a lateral cutaway of side detail of closeable connectionshowing open egress of upstream drain;

FIG. 10 shows a front detail view of connector in upward connectionconfiguration;

FIG. 11 shows an isometric view of sink and trap in upward connectionconfiguration with cleanout cap in;

FIG. 12 shows an isometric view of sink and trap in upward connectionconfiguration with cleanout cap out;

FIG. 13 shows an isometric view of sink and trap in upward connectionconfiguration with blocker out;

FIG. 14 shows an isometric view of sink and trap in upward connectionconfiguration with blocker inserted;

DETAILED DESCRIPTION OF THE INVENTION

In some embodiments, aspects of the invention described in thisApplication comprise a system with a water supply in the form of afaucet, a perforated vessel in the form of a sink, and a drain systemconnected to a usually vertical drainage stack pipe contained in thewall in front of which is installed the sink. In the figures following,the water supply is not pictured and the drainage stack, eitherhorizontal or vertical behind the wall, is also left out, owing in bothcases to the diversity of solutions not relevant to this Invention.

In FIG. 1 , a sink 3 is attached to a wall 1. The tailpiece of the sinkdrain 5 is attached slidingly with a compression seal tightened by a nut7 threaded onto an external thread ring around the top of an upstreamexpansion hub 9 on a U-bend 11 of pipe or tube to allow adjustment ofthe vertical position of the trap and downstream drainset to the idealposition determined by the vertical position of the downstreamconnection to a stub of pipe protruding from the wall, also called awall stub out, that leads to the vertical drainstack leading to adownstream sewer. The U-bend 11 is also equipped with a downstreamrotating juncture 13 tightened with a nut 15 that allows for angleorientation of the downstream wallbend 17 in a nearly horizontal plane.A wallbend 17 is comprised of a ninety degree bend 19 and straight 21.Usually, the wall bend is one piece; in FIG. 1 the straight 21 is aseparate piece slidingly attached to a upstream ninety degree elbow 23with another compression seal tightened with a nut 25 contiguous with anexpansion 27 that also allows for horizontal adjustment. The downstreamend of the horizontal straight 21 is attached to the connector Invention29 described in this Application by a plurality of means including butnot limited to a compression seal (shown here) or soldering of brass orsolvent cementing of plastic of the straight tube or pipe into theconnector hub. A cleanout cap 31 is displayed in this configuration. Thenut 35 tightens a sliding compression seal, just one of the many meansof connecting a tube or pipe to a hub.

FIG. 2 shows an isometric view of sink and trap in a side connectionwhere 1 is the wall upon which the sink 3 is mounted, and in the innerbowl 37 of the sink begins a drain system connected to the connector 29Invention described in this Application stopped up by a sealing cleanoutcap 31 providing a plurality of uses including but not limited tocleaning out of the drain system with plumbing cleaning tools. Thedownstream hub of the connector is connected to a wall stub out 39 oftube or pipe emanating horizontally from the wall 1 perforated by a hole41 and connected to a usually vertical drainage stack pipe, not shown.

FIG. 3 shows an isometric view of a sink 3 the drain of which isultimately connected to a connector 29 constituting this Invention. Acleanout cap 31 is threaded off an external thread ring 43 on theconnector 29.

FIG. 4 shows an isometric view of a sink the drain of which is connectedto the connector 29 in this Invention. The cleanout cap is replaced witha blocker that threads into the thread ring 43 on the connector 29. Herethe blocker is not yet connected.

FIG. 5 shows an isometric view of a sink 3 the drain of which isconnected to the connector 29 in this Invention. The cleanout cap isreplaced with a blocker 45 that threads over the thread ring on theconnector 29. Here the blocker 45 has been threaded over the connector,although a plurality of connection methods is possible. The effect ofthis blocker 45 is to block the downstream egress of chemical solutionspoured into the sink. The sealing off of the drain need not be asthorough as with a valve, for the following reason. In order to get anear perfect seal such as found on a packed valve, the packing of thevalve must be quite tight. Packing is comprised of seals that arecompressed to effect seal on a rotary moving part. This makes theturning of the valve difficult. For tubes as large as the inch and onequarter or inch and one half found normally in sink plumbing, the amountof torque required to turn a handle under such sealing packing,particularly in older drainsets, is near the limit of hand strength toturn. This in itself is not a problem, but the reality of drainsets inany healthcare setting is that the drainset itself, the drainage stackbehind the wall, and the various connections found within, were neverdesigned to withstand torque. Indeed, with years of cleaning with strongcleaning chemicals, wallbend wall thickness can approach that of paper.Cracks in the drainset introduced by torqueing in front of the wall canbe fixed, but cracks introduced behind the wall can result not only inleaks, but in the spread of drain pathogens along unknowable pathsthroughout a healthcare building. Additionally, valves are dirty—it isimpossible to keep bacteria out of a valve and just as impossible tosanitize it. Accordingly, it is the intention of this Invention tosupply a blocker 45 that temporarily connects to the connector 29 by aplurality of methods including but not limited to a sealing threadmateconnection, where the sealing of drainwater egress can be effected by acylinder within cylinder blocking of a side port of the connector 29,constituting a sufficient seal to keep the disinfectant chemicals withindrainset for a matter of hours instead of the days or longer that can beachieved with a packed valve.

In FIG. 6 , a sink 3 is attached to a wall 1. The tailpiece of the sinkdrain 5 is attached slidingly with a compression seal tightened by a nut7 threaded onto an external thread ring around the top of an upstreamexpansion hub 9 on a U-bend 11 of pipe or tube to allow adjustment ofthe vertical position of the trap and downstream drainset to the idealposition determined by the vertical position of the downstreamconnection to a wall stub out. The U-bend 11 is also equipped with adownstream rotating juncture 13 tightened with a nut 15 that allows forangle orientation of the downstream wallbend 17 in a nearly horizontalplane. A wallbend 17 is comprised of a ninety degree bend 19 andstraight 21. Usually, the wall bend is one piece; in this figure thestraight 21 is a separate piece slidingly attached to an upstream ninetydegree elbow 23 with a compression seal tightened with a nut 25. The endof the straight 21 is attached to a distal downstream ninety degreeelbow by a plurality of means including but not limited to a compressionseal tightened by a nut 35. On the downstream, downward orientated portof a ninety degree elbow is another nut 33 that threads onto the threadring on the sideport of the connector 29 Invention. A cleanout cap 31 isdisplayed in this configuration. There is a disadvantage to thisconfiguration—the wall stub out position may be too high for the upwardconfiguration of the connector to be used without placing the new sinkon the wall too high off the floor. Otherwise, if the wall stub out issufficiently low to accommodate the upward configuration of theconnector 29, a great advantage is obtained by the introduction of asecond rotating seal that is sealed by a compression nut 33. If the wallstub out is an angle originally introduced to accommodate the drainsetof the sink 3 being replaced, this angle can be otherwise be impossibleto match orthogonally, requiring poor plumbing practice such as flexibleconnectors to enable the straight 21 to be connected to the wall stubout. While not obvious in design, in practice this orientation challengeis common. In extreme cases, the entire wall 1 must be ripped out, andthe hidden drainage stack rerouted with forty-five degree elbows toprovide a wall stub out connection that lines up with the new sink.While possible, it is an expensive and time-consuming modification; aswell, the disturbing of drywall is a risk for transmission of otherairborne pathogens. Instead, use of the connector Invention described inthis application can provide the three dimensional flexibility oforthogonal connectivity for a small price, with the advantage of theblockable functionality for chemical cleaning that works.

Toward an explanation of the blocking functionality, FIG. 7 shows a sideview of sink and trap in the upward connection configuration. A wall 1supports a sink 3, usually with additional support structures not shownhere, and the connector 29 with a closed cleanout cap 31 is attached viaa compression seal tightened with a nut 47 or other connection to a wallstub out 39 itself connected downstream to a usually vertical drainagestack. FIG. 7 also illustrates the three features of the connector 29:the cleanout port 61, the side upstream port 63, and the downstream port65.

A detail of the same side view with a lateral cutaway 49 of theconnector 29 described in this Application with a blocking plug 45inserted into the cleanout port of the connector 29. The cutaway of theconnector 29 wall reveals that the cylinder 51 of the blocking pluginterrupts the flow of drainwater exiting the sink into the drainsystem. While the seal of an outer diameter controlled tube in aninternal diameter controlled machined casting is a matter of thetolerance of machining chosen upon, with an appropriate tolerance aneffective seal can be achieved that will keep a dose of chemicalcleaners in the trap and wall bend for as long as takes to scour thebacteria off the internal walls of the drainset, avoiding the heavytorqueing as well as biofilm growth involved in a packed valve. Thequestion of what to do with the blocker plug after cleaning depends onthe materials used in the drainset. For example, a brass blocker plugcan be sterilized in a bucket of chemicals, or in an autoclave, and thenrecycled.

FIG. 9 shows the same lateral cutaway 49 of the connector 29 where theplug connector has been removed, showing the upstream egress port 53comprised by the internal diameter of the wallbend straight.

FIG. 10 shows a front detail of the connector invention in thisApplication in the upward connection configuration. A ninety degreeelbow 49 is attached to the connector 29 in this Application by means ofa nut 33 tightening against seal by threading with a clockwise tighten55 onto a thread ring provided on the connector side port to supply aseal. This also allows for an orthogonal connection of the straight tubeinto the upstream hub 57 no matter what the angle of the wall stub outrelative to the wall, without a flexible connection. In normal use thecleanout cap 31 threads in against a seal in the connector.

FIG. 11 shows an isometric view of the sink and drainset showing acleanout cap 31 threaded onto the connector 29.

FIG. 12 shows an isometric view of the sink and drainset showing acleanout cap 31 threaded out of the connector 29 to allow for insertionof a blocking plug.

FIG. 13 shows an isometric view of the sink and drainset showing ablocking plug 45 about to be inserted into the open port of theconnector 29 described in this Application.

FIG. 14 shows an isometric view of the sink and drainset showing ablocking plug 45 inserted into the port of the connector 29 described inthis Application, in preparation for cleaning treatment.

In practice, opening a drainset requires a bucket with bleach in thebottom to catch leaks when the blocking plug is removed and the cleanoutcap is replaced.

Accordingly, this Application presents a connector invention thatprovides a blocking functionality that allows for a thorough soaking ofthe drainset with appropriate cleaning chemicals over the needed periodof time. Since the wall bend is angled to drain, the blocking plug canbe designed in a plurality of ways to allow for flow while stillinserted. This would be important if a series of different chemicaltreatments is required. The blocking plug could be shifted from open toclosed to open for each stage of chemical treatment without entirelyremoving the blocking plug until the end of the treatments. Additionaltechnology such as pathogen diagnostic reagents, battery poweredultraviolet light are also possible.

What is claimed is:
 1. A ninety degree connector to connect a downstreamstraight tube of a sink drainset to a horizontal wall stub of pipeemanating from a healthcare room wall connected on the downstream end toa drainage stack leading to a sewer, and, a cleanout port on theconnector sharing a centerline with the wall-stub and diametricallyopposed to the downstream connection port of the connector, closed witheither a cleanout cap or a blocking plug connected by one of a pluralityof methods including but not limited to a sealing thread mate, where theblocking plug cylinder blocks egress of drainwater plug from theupstream port of the connector draining perpendicular to the centerlineof the blocking plug.
 2. As in claim 1, excepting that a second ninetydegree elbow is attached to the upstream port of the connector using arotating compression basket nut and seal threading to an external threadon the upstream port of the connector such that the center line of theupstream port is vertical and parallel to the heathcare room wall.
 3. Asin claim 1 or claim 2, with a blocking plug configured to block or allowegress of drainwater when the plug is inserted into and connected to thecleanout port, by means of rotation of the plug in its insertedposition.
 4. As in claim 1 or claim 2, with a blocking plug configuredwith a plurality of antimicrobial technology including but not limitedto pathogen diagnostic technology or pathogen kill technology.